Integrated process for making inflatable article

ABSTRACT

An integrated process for making an inflatable laminated article comprises extruding a first film and a second film, followed by cooling the first film and the second film so that the films will not fuse to one another upon contact with each other. The films are then brought into contact with one another, and selected portions of one or both films are heated so that the films are heat sealed to one another in a selected area having a desired pattern. The unsealed area between the film provides inflatable chambers between the first film and the second film. An alternative process utilizes a film tubing in lay-flat configuration to produce a laminated inflatable article.

FIELD OF THE INVENTION

[0001] The present invention relates generally to methods of makinglaminated film articles, apparatus for making laminated film articles,and more particularly, to apparatus and methods for making laminatedfilm articles having inflatable chambers and channels.

BACKGROUND OF THE INVENTION

[0002] Conventional cushion materials include thermoformed sealedlaminate articles such as Bubble Wrap® cushioning material. However, itis also known to prepare laminated inflatable articles which can beshipped to a packer uninflated, and inflated immediately before use.Such inflatable articles are typically made from two heat sealable filmswhich are fused together in discrete areas to form one or moreinflatable chambers.

[0003] Conventional methods of making cushion material, such as BubbleWrap® cushioning material, use a vacuum source to deform polymer film toform bubbles or pockets that can be filled with air (or other gases) toform bubbles. Such products can be made using a heated drum havingrecesses that are connected to a vacuum source. When vacuum is applied,each of various regions of the heated film in contact with the drum isdrawn into a recesses on the drum. The heated film is deformed andthinned in the regions drawn into the recess by the vacuum process. Oneside of the resulting film remains “flat”, while the other side is notflat, but rather is “thermoformed”. A second film, which preferably is aflat film, i.e., not thermoformed, is fused to the “flat side” of theformed film, resulting in a plurality of sealed, air-filled “bubbles.”

[0004] Conventional cushion fabricating processes also include a firststage film fabrication step and a separate second stage fusing step. Inthe first stage, polymer films are fabricated by conventional techniquesknown to those in the art of polymer film fabrication. In the secondstage, the polymer films are combined according to heat sealing methodsthat are known to those in the art of polymer film sealing techniques.

[0005] Two-stage manufacturing processes are undesirable because of theadded cost and inefficiency associated with the process. During twostage processes, films are fabricated and wound onto rolls at onelocation, and unwound and combined with a second film to make acushioning material at a second location. The processes are inefficientin that they include winding and unwinding of rolls of film, togetherwith inventorying and transporting, as well as other inefficienciesassociated with two-stage processes.

SUMMARY OF THE INVENTION

[0006] The present invention overcomes the inefficiencies and otherdetriments described above with an integrated, one-stage process formaking an inflatable laminated inflatable article. The process of theinvention uses a single stage to go from polymer extrusion to form thefilm or films, thereafter sealing the film or films together to forminflatable chambers between the films.

[0007] As a first aspect, the present invention is directed to anintegrated process for making an inflatable laminated article,comprising the steps of: (A) extruding a first film and a second film;(B) cooling the first film and the second film so that the films willnot fuse to one another upon contact with each other; (C) contacting thefirst film with the second film; (D) heating selected portions of atleast one of the first and second films to a temperature above a fusiontemperature, so that the first and second films are heat sealed to oneanother at a selected area, with the selected area providing a heat sealpattern in which the unsealed portions between the films provideinflatable chambers between the first film and the second film. Ofcourse, if one or more of the films are multilayer films having asealing layer, the heating of such film need only be to a temperatureabove the fusion temperature of at least the seal layer of one or moreof the films.

[0008] While it is preferred to have the C and D steps in this order,they may be reversed in order, i.e., by first heating selected portionsof at least one of the films followed by contacting the first film withthe second film so that the first and second films are heat sealed toone another at selected areas. Moreover, the selected areas need notcorrespond exactly with the selected portions which are heated. That is,the portions which are heat sealed may be slightly larger or slightlysmaller than the selected portions which are heated.

[0009] While the cooling can be active (e.g., contacting one or morefilms with one or more chilled rolls, belts, the use of cool air orwater, etc.), it can also be passive, e.g., simply providing the firstand second films enough time to cool under ambient conditions so thatthey do not fuse to one another upon contact. Thereafter, in order toheat seal the films to one another, it is necessary to heat at least theseal layers of one or both of the films to a temperature at or above atemperature at which the one or more of the seal layers will fuse.

[0010] Preferably, the first and second films are extrudedsimultaneously. Although it is possible to extrude both films from thesame extruder (followed by separation from one another), preferably thefirst and second films are extruded using separate extruders. Either orboth the first and second films can be extruded using an annular die ora slot die, i.e., as an annular film or as a flat film, respectively. Ifan annular die is used, the resulting lay-flat tubing can either beself-welded into a flat film, or converted to a flat film by being slitin the machine direction.

[0011] Preferably, the contacting of the first film with the second filmis carried out by forwarding the first film and second film together atthe same speed. Although heating of selected portions of one or more ofthe films can be carried out before the films contact one another,preferably the heating of the selected portions of the first and secondfilms is carried out while the first and second films are in contactwith one another, with the heat sealing being carried out using acombination of heat and pressure. In one embodiment, the contacting stepand the heating step are performed simultaneously, with pressure beingsimultaneous with the heating, resulting in contacting and heat sealingbeing essentially simultaneous. During sealing, preferably heat andpressure are applied simultaneously.

[0012] Preferably, heating is performed by passing the first and secondfilms together through a nip between a first roll and a second roll,with at least one of the rolls having a patterned raised surface and atleast one of the pair of rolls being heated. Preferably the patternedroll is heated. However, both the first roll as well as the second rollcan be provided with a raised surface, with the raised surfaces beingoperatively aligned to heat seal the selected portions of the first filmand the second film. Preferably, each roll with a raised surface has acontinuous raised surface so that the nip between the first and secondrolls is maintained throughout rotation of the first and second rolls,without further means to maintain the nip. If a roll does not have araised surface, preferably such roll has a smooth continuous surface toensure that the nip is maintained throughout rotation of the roll.Alternatively, means can be provided to maintain the nip betweenirregular rolls, such as a resilient surface on one or more of therolls, and/or a roll on a moveable axis with force continuously urgingthe rolls into contact with one another despite irregularities.Preferably, the first and second films are heat sealed to one another ina repeating pattern of sealed and unsealed areas.

[0013] As a second aspect, the present invention is directed to anintegrated process for making an inflatable laminated article,comprising the steps of: (A) extruding a tubular film having an outsidesurface and en inside surface; (B) cooling the tubular film to atemperature low enough that the inside surface of the tubular film iscool enough not to adhere to itself; (C) placing the tubular film intothe lay-flat configuration having a first lay-flat side and a secondlay-flat side, so that a first inside lay-flat surface of the firstlay-flat side of the tubular film is in contact with a second insidelay-flat surface of the second lay-flat side of the tubular film; and,(D) heating sealing selected portions of the first lay-flat side of thetubular film to the second lay-flat side of the tubular film, the heatsealing being carried out to provide a pattern of sealed and unsealedareas with the unsealed areas providing inflatable chambers between thefirst lay-flat side of the tubular film and the second lay-flat side ofthe tubular film. Depending upon the pattern of the heat sealing, theresulting heat sealed (i.e., laminated) article may or may not have tobe slit along one or both side edges (i.e., slit in the machinedirection) in order to provide access for means for inflating theinflatable chambers. The second aspect of the present invention ispreferably otherwise carried out in accordance with preferred featuresset forth above in the first aspect of the present invention.

[0014] As a third aspect, the present invention is directed to anintegrated process for making an inflatable laminated article,comprising the steps of: (A) extruding a flat film having a first outersurface and a second outer surface; (B) cooling the film so that thefirst outer surface is cool enough not to adhere to itself upon beingdoubled back against itself; (C) folding the film to make a crease in amachine direction of the film, with a first leaf of the film being on afirst side of the crease and a second leaf of the film being on a secondside of the crease, the first leaf being flat against the second leaf sothat the first outer surface is doubled back against itself; and (D)heating sealing selected portions of the first leaf to the second leaf,the heat sealing being carried out to provide a pattern of sealed andunsealed areas with the unsealed areas providing inflatable chambersbetween the first leaf and the second leaf. The third aspect of thepresent invention is also preferably carried out in accordance withpreferred features set forth above in the first aspect of the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The numerous features and advantages of the present invention arebetter understood by those skilled in the art by reference to theaccompanying detailed description and the following drawing, in which:

[0016]FIG. 1 is a flow chart illustrating aspects of one stageintegrated methods of making laminate materials.

[0017]FIG. 2 is a diagrammatic view of one embodiment of an exemplarylaminate manufacturing system.

[0018]FIG. 3 is a diagrammatic view of another embodiment of anexemplary laminate manufacturing system.

[0019]FIG. 4 is a diagrammatic view of another embodiment of anexemplary laminate manufacturing system.

[0020]FIG. 5 is a diagrammatic view of another embodiment of anexemplary laminate manufacturing system.

[0021]FIG. 6 is a diagrammatic view of another embodiment of anexemplary laminate manufacturing system.

[0022]FIG. 7 is diagrammatic view of exemplary laminate manufacturingapparatus.

[0023]FIG. 8 is a diagrammatic view of a portion of the manufacturingprocess.

[0024]FIG. 9 is a diagrammatic view of another embodiment of a laminatemanufacturing apparatus.

[0025]FIG. 10 is a diagrammatic view of a particularly preferredlaminate manufacturing process.

[0026]FIG. 11 is an exemplary film manufacturing apparatus using atubular stock of film to fabricate laminate material.

[0027]FIG. 12 is an exploded diagrammatic view of an exemplary laminatematerial.

[0028]FIG. 13 is a diagrammatic view of a section of an inflatablearticle.

DETAILED DESCRIPTION

[0029] Methods of making protective polymeric laminates, the laminatesthemselves, and apparatus for making the protective laminates aredisclosed. Protective laminates are made from two films, or from tubularstocks of film, in a one stage integrated in-line process. The laminatesare composed of discrete films sealed to each other in selected sealregions, forming a pattern of sealed and unsealed portions, the latterof which define chambers, inflation channels, connecting passageways, aninflation skirt, and optionally one or more inflation manifolds that canbe inflated, thereby ultimately (i.e., upon inflation and sealing toentrap the inflation gas or fluid) providing cushioning pockets orbubbles within the laminate. The present methods fabricate laminatematerials from polymeric resins in a one stage process that eliminatesdisadvantages associated with multiple stage processes.

[0030]FIG. 1 is a flow chart illustrating various steps of the one-stageintegrated method of making inflatable laminated articles in accordancewith the first aspect of the present invention. Reference numerals 1through 6 are employed to indicate the steps. The method of making theinflatable laminated article is carried out by extruding two films 1;cooling the films to a temperature below the fusing temperature of eachof the films 2; contacting the first and second films to each other 3,heating selected portions of the films 4, sealing the select heatedportions of the first film to the second film 5, and cooling the filmsto form the laminate material 6. Although cooling step 6 can be passive(e.g., in that the heat seals are simply allowed to cool by giving offheat to the ambient environment), it is preferably active in order toquickly cool the heat seals immediately after formation, so that theheat seal is not damaged or weakened by continued processing.

[0031]FIG. 2 is a diagrammatic view of one embodiment of an exemplarylaminate manufacturing system 10 a. Referring to FIG. 2 to illustratemethods of the present invention, the laminate manufacturing system 10 acomprises extruders 11 and 11′, first and second films 12 and 13,transfer roller pairs 14 and 14′, contact roller 15, and raised surfaceroller 16. First and second films 12 and 13 are extruded from separateextruders 11 and 11′, respectively. After exiting extruders 11 and 11′,first and second films 12 and 13 are cooled to a temperature just belowthe fusing temperature of layers 12 and 13. Films 12 and 13 can beactively cooled by one or more of transfer rollers 14 or by exposure toambient conditions. Transfer roller pairs 14 and 14′ guide first andsecond films 12 and 13 to nip 17 formed between contact roller 15 andraised surface roller 16. As films 12 and 13 pass through nip 17,pressure is applied to selected areas of both of films 12 and 13 whilesimultaneously heat is applied to at least one of films 12 and 13through at least one of rollers 15 and 16, so that heated portions offilms 12 and 13 are heat sealed to form heat seals in the sealed area,and inflatable chambers, passageways, etc in the unsealed area.

[0032] The present invention is inclusive of the heat sealing of twomonolayer films to one another, heat sealing a multilayer film to amonolayer film, and heat sealing two multilayer films to one another.

[0033]FIG. 3 is a diagrammatic view of another embodiment of anexemplary laminate manufacturing system 10 b. First and second films 12and 13 contact one another before first film 12 contacts raised surfaceroller 16. Raised surface roller 16 heats selected portions of firstfilm 12 and simultaneously heats selected portions of second film 13that correspond to the heated portions of first film 12.

[0034]FIG. 4 is a diagrammatic view of an embodiment of alternativelaminate manufacturing process 10 c. In FIG. 4, first film 12 contactsraised surface roller 16 before first film 12 contacts second film 13.Selected portions of first film 12 are heated by raised surface roller16 before first film 12 contacts second film 13, by advancing first film12 partially around raised surface roller 16 before passing films 12 and13 through nip 17.

[0035]FIG. 5 is a diagrammatic view of another alternative process 10 dfor making an inflatable article. In FIG. 5, first and second films 12and 13 are in mutual contact when first film 12 contacts raised surfaceroller 16 before the films enter nip 17. First film 12 and second film13 are heated by raised surface roller 16 as they are advanced throughnip 17 between raised surface roller 16 and associated smooth nip roller15.

[0036]FIG. 6 is a diagrammatic view of another alternative process 10 efor making an inflatable article. In FIG. 6, the process furtherutilizes cooling roller 18 to cool the heat sealed laminate 20 shortlyafter sealing. First and second films 12 and 13 pass between nip 17where selected portions of films 12 and 13 are heat sealed. The heatedportions of films 12 and 13 are cooled, by cooling roller 18, to atemperature below the fusing temperature of films 12 and 13. In anotherembodiment (not illustrated), cooling roller 18 forms a nip with raisedsurface roller 16.

[0037] The one-stage process of the present invention eliminates theneed to wind-up component films 12 and 13 after extrusion but beforelamination, as well as the need for transporting and unwinding suchintermediate products. The integrated process involves controlling thetemperature of the component films during fabrication, thereby providingfilms that are not stressed during fabrication as in conventionaltwo-stage processes. Preferably, the films are maintained at atemperature close to the fusing temperature of films, to minimize thestresses placed on the films. Minimizing temperature fluctuations yieldslaminate materials that are stronger and more durable than conventionalpackaging materials. The laminate materials made by the present methodsare not inflated, which permits shipping an intermediate product orrelatively high density but which is ready for inflation at the locationof the end-use, and this is more efficient than shipping a low densityinflated product.

[0038] The methods and apparatus of the present invention can beoperated at a higher output than conventional processes, including forexample film outputs of more than 250 feet in length of film per minute.In addition, the methods produce larger width films than conventionalprocesses, including for example, widths greater than 36 inches. Theincrease in film width and in rate of film produced thereby permits anincrease in the surface area of laminated material produced moreefficiently and at lower cost compared to conventional methods.

[0039]FIG. 7 is diagrammatic view of an alternative laminatemanufacturing apparatus 19 a. FIG. 8 is an diagrammatic view of analternative arrangement nip 17. The methods described herein areperformed by an apparatus capable of adjusting the temperature of filmsto maximize film fabrication speeds. Referring to FIG. 7 and FIG. 8,apparatus 19 a for making laminate material 20 comprises extruder 11,transfer roller pairs 14 and 14′, contact roller 15, raised surfaceroller 16, and collection roller 21. Contact roller 15 and raisedsurface roller 16 are operatively associated to form nip 17 whichdefines sealing zone 22.

[0040]FIG. 9 is a diagrammatic view of another embodiment of a laminatemanufacturing apparatus 19 b. Referring to FIG. 9, apparatus 19 bcomprises extruders 11 and 11′, transfer roller pairs 14 and 14′,contact roller 15, raised surface roller 16, cooling roller 18, andcollection roller 21.

[0041] Referring to FIG. 7, FIG. 8, and FIG. 9, transfer roller pairs 14and 14′ are conventional rollers familiar to persons skilled in the artof polymer film fabrication. With reference in particular to FIG. 7, thepresent invention is not limited to one transfer roller 14 or 14′, butrather encompasses one or more rollers that guide films 12 and 13 to nip17 as will be understood by persons familiar with film processingtechnology.

[0042] In one embodiment films 12 and 13 are cooled by transfer rollerpairs 14 and 14′, the cooling being to a temperature below the fusingtemperature of each of films 12 and 13. Transfer roller pairs 14 and 14′are heat transfer rolls, cooled by conventional methods, such as coldwater circulated through the rolls. In embodiments of the presentinvention having more than one transfer roller, it is preferred thattransfer roller pairs 14 and 14′ immediately prior to nip 17 cool films12 and 13 to a temperature below the fusing temperature of each of films12 and 13.

[0043] Referring to FIG. 7, FIG. 8, and FIG. 9, contact roller 15opposes raised surface roller 16 and is operatively associated withraised surface roller 16 to form nip 17. Contact roller 15 appliespressure to films 12 and 13 as the films pass through nip 17. Thepresent invention is not limited to contact roller 15, but ratherencompasses other contact surfaces formed on other apparatus, such as aplaner surfaces, curved surfaces, or portion of a clamp, as will beunderstood by persons familiar with film processing technology in viewof the present disclosure.

[0044] With reference in particular to FIG. 8, contact roller 15preferably has an elastic outer layer 23. More preferably, the elasticouter layer 23 is a smooth rubber layer. The elastic outer layer 23 isdeformable and readily conducts heat. The rubber outer layer 23 providesheat transfer to the second layer 13 and diminishes the tendency ofadherence of the second layer of film 13 to contact roller 15.

[0045] With reference in particular to FIG. 8, raised surface roller 16comprises raised surfaces 24, recesses 25, and recessed surfaces 26.Raised surface roller 16 is a heat transfer roller and is heated byconventional heating apparatus, as will be understood by personsfamiliar with plastic film and roller heating technology. Preferablyraised surface roller 16 is heated by hot oil.

[0046] The present invention is not limited to heat sealing using raisedsurface roller 16, but rather encompasses alternative forms of heatsealing apparati, including impulse sealing apparati, ultrasonicsealing, etc. The sealing means need not continuously seal the filmstogether, but rather can carry out the sealing intermittently. Moreover,the raised surface roller could alternatively be a planer surface,curved surface, or portion of a clamp, as will be understood by personsfamiliar with film processing technology in view of the presentdisclosure. The raised surface roller or plate does not require a sourceof vacuum.

[0047] The methods of the present invention have an advantage overconventional methods of making protective laminates and bubble filmbecause the present methods do not require thermoforming of thestructure of the laminate material during the heat sealing process byvacuum stretching the films. However, the present invention is notlimited to methods that do not distort, deform the films, but ratherencompasses conventional vacuum stretching techniques as will beunderstood by persons familiar with film processing technology in viewof the present disclosure.

[0048] Raised surfaces 24 and recessed surfaces 26 form a patterned heatseal 27 in laminate material 20 as explained more fully below withreference to FIG. 13. Raised surfaces 24 extend away from recessedsurfaces 26 thereby forming a pattern for the heat seal(s) to be made toform the inflatable article. The pattern formed by raised surface 24 issuch that raised surfaces 24 are in contact with contact roller 15 whenraised surface roller 16 is in contact with contact roller 15. Recesssurfaces 26 are not in contact with contact surface 16 when raisedsurface roller 16 contacts contact roller 15.

[0049] With reference in particular to FIG. 8, in one embodiment of thepresent invention, raised surface roller 16 further comprises a releasecoating 28 that reduces adherence with film 12 while film 12 contactsraised surface roller 16, and particularly when film 12 releases fromroller 16. A portion of release coating 28 is infused with one or morepolymers. The polymer infused can be any conventional polymer used forreducing adherence to polymer films, for example, Teflon®polytetrafluoroethylene. Raised surface roller 16 can be infused by anyconventional infusion process. Preferably, the raised surface of roller16 is textured to reduce adherence to polymer films, as discussed inmore detail below.

[0050] In an alternative embodiment of the present invention (notillustrated), contact roller 15 has raised surfaces that correspond toraised surfaces 24. Contact roller 15 has recesses and recessed surfacesthat correspond with recesses 25 and recessed surfaces 26.

[0051] Referring to FIG. 7 and FIG. 8, raised surface roller 16 andcontact roller 15 are operatively associate to form a nip 17. The term“nip” as used herein refers to an area between two rollers. First film12 and second film 13 are in contact as they pass though nip 17. Asfirst and second films 12 and 13 pass through nip 17, heat and/orpressure are applied to the films such that selected portions of firstand second films 12 and 13, fusing the films together to form patternedheat seals 27.

[0052] In FIG. 9, extruders 11 and 11′ are conventional extruder. Firstand second films 12 and 13 can be extruded as monolayer films,coextruded as multilayered films, extruded through an annular die orslot die, or extrusion coated which are familiar to persons familiarwith plastic film manufacturing technology. In one embodiment first andsecond films 12 and 13 are toughened by crosslinking via chemicalcross-linking or irradiation techniques known to those of skill in theart.

[0053] In the embodiment as shown in FIGS. 2-7, and 9 extruder 11 can beone or more extruders.

[0054] In another embodiment as shown in FIG. 11, a film tubing, inlay-flat configuration, is of course integrally joined at its edges.However, the two lay-flat sides are used to form laminated inflatablearticle 20. In such a process, only one extruder is needed, the extruderfeeding a molten stream of polymer to an annular die from which the filmtubing is extruded. Optionally, a second extruder can be used toextrusion coat the tubular film with one or more film layers byextrusion coating techniques known to those skilled in the filmfabrication arts.

[0055]FIG. 10 is a schematic of a particularly preferred apparatus andprocess (50) for carrying out the present invention. In FIG. 10,extruders 52 and 54 extrude first film 56 and second film 58,respectively. After extrusion, film 54 makes a partial wrap around heattransfer (cooling) roller 60, which preferably has a diameter of 8inches and which is maintained at a surface temperature well beneath thefusion temperature of the extrudate, e.g., from 100-150° F. Second film56 makes partial wraps around each of heat transfer (cooling) rollers 62and 64, each of which has a diameter of 8 inches and each of which ismaintained at a surface temperature similar to that of cooling roller60. After cooling, first film 56 makes a partial wrap (about 90 degrees)around Teflon® coated rubber nip roll 66, which has a diameter of 8inches and which has, as its primary function, maintaining nip with heattransfer (heating) raised surface roll 70. While first film 56 ispassing over nip roll 66, second film 58 merges with first film 56, withboth films together being wrapped for a short distance around nip roll66 before together entering first nip 68. Nip roller 66 provides alocation of films 56 and 58 to come together without being marred ordistorted.

[0056] Thereafter, second film 58 makes direct contact with raisedsurface roll 70 (which is illustrated as a smooth roll only forsimplicity of illustration). First nip 68 subjects films 56 and 58 to apressure of from 2 to 10 pounds per linear inch, preferably 2 to 6pounds per linear inch, more preferably about 4 pounds per linear inch.

[0057] Films 56 and 58 together contact raised surface roll 70 for adistance of about 180 degrees. Raised surface roll 70 has a diameter of12 inches, is heated by circulating hot oil therethrough so that thesurface is maintained at a temperature of from 280° F. to 350° F., andhas edges of the raised surfaces being rounded over to a radius of{fraction (1/64)} inch. Raised surface roll 70 has a Teflon®polytetrafluoroethylene coating thereon, with the raised surfaces beingabove the background by a distance of ¼ inch (0.64 cm). Moreover, theraised surface of raised surface roll 70 is provided with a surfaceroughness of from 50 to 500 root mean square (i.e., “rms”), preferably100 to 300 rms, more preferably about 250 rms. This degree of roughnessimproves the release qualities of raised surface roll 70, enablingfaster process speeds and a high quality product which is undamaged bylicking back on roll 70.

[0058] The raised surface heats that portion of film 58 which contactsthe raised surface of roll 70. Heat is transferred from raised surfaceroll 70, through a heated portion of film 58, to heat a correspondingportion of film 56 to be heat sealed to film 58. Upon passing about 180degrees around raised surface roll 70, heated films 58 and 56 togetherpass through second nip 72, which subjects heated films 58 and 56 toabout the same pressure as is exerted in first nip 68, resulting in apatterned heat seal between films 56 and 58.

[0059] After passing through second nip 72, films 58 and 56, now sealedtogether, pass about 90 degrees around heat transfer (cooling) roller74, which has a diameter of 12 inches and which has cooling waterpassing therethrough, the cooling water having a temperature of from100° F. to 150° F. Cooling roller 74 has a ¼ inch thick (about 0.64 cmthick) release and heat-transfer coating thereon. The coating is madefrom a composition designated “SA-B4”, which is provided and applied toa metal roller by Silicone Products and Technologies Inc of Lancaster,N.Y. The coating contains silicone rubber to provide cooling roller 74with a Shore A hardness of from 40 to 100, preferably 50-80, morepreferably 50-70, and still more preferably about 60. The SA-B4composition also contains one or more fillers to increase the heatconductivity to improve the ability of cooling roller 74 to cool thestill hot films, now sealed together to result in inflatable article 76,which is thereafter rolled up to form a roll for shipment and subsequentinflation and sealing, to result in a cushioning article.

[0060] In order to carry out the process at relatively high speed, e.g.,speeds of at least 120 feet per minute, preferably from 150 to 300 feetper minute, but up to as high as 500 feet per minute, it has been foundto be important to provide the manufacturing apparatus with severalfeatures. First, the raised surface roll should be provided with arelease coating or layer, and to also avoid sharp edges which interferewith a clean release of the film from the raised surface roll. As usedherein, the phrase “release coating” is inclusive of all releasecoatings and layers, including polyinfused coatings, applied coatingssuch as brushed and sprayed coatings which cure on the roll, and even arelease tape adhered to the roll. A preferred release coatingcomposition is Teflon® polytetrafluoroethylene. Second, the edges of theraised surfaces should be rounded off to a radius large enough that thefilm readily releases without snagging on an edge due to its “sharpness”relative to the softened film. Preferably, the radius of curvature isfrom {fraction (1/256)} inch to ⅜ inch, more preferably from {fraction(1/128)} inch to {fraction (1/16)} inch, more preferably from {fraction(1/100)} inch to {fraction (1/32)} inch, and more preferably about{fraction (1/64)} inch, i.e., about 0.04 cm. It is also important toprovide the cooling roller downstream of and in nip relationship withthe raised surface roller, with a release coating or layer, as describedabove.

[0061] The process and apparatus illustrated in FIG. 10 can also besupplemented with additional optional components and steps. Moreparticularly, one or both of films 58 and 62 can be preheated to atemperature below their fusing temperature, so that less heat need beadded by raised surface roller 70. In this manner, the process can beoperated at higher speed, and/or the heat seal may be made stronger orof otherwise higher quality. Preheating can be carried out by, forexample, providing nip roller 66 with heating characteristics inaddition to providing raised surface roller 70 with heatingcharacteristics. Optionally, additional nips can be provided againstraised surface roller 70, to provide additional pressure points for theformation of strong heat seals at high manufacturing speeds.

[0062]FIG. 11 is a diagrammatic view of an exemplary film manufacturingapparatus using a tubular stock of film to fabricate laminate material.Referring to FIG. 11, extruder 11 comprises resin hopper 30, body 31,and die 32. Extruder 11 can be any conventional extruder, including forexample, single screw, double screw, and/or tandem extruders. In anotherembodiment, one or more extruders connected to die 32 co-extrude, asmultilayer film or monolayer film, polymers having different propertiesor compositions.

[0063] Referring to FIG. 11 to illustrate methods of extruding films,films are fabricated by providing resin pellets 33 to resin hopper 30 ofextruder 34, from which resin pellets 33 are fed into extruder 34. Resinpellets 33 are melted in extruder 34 to form a molten resin stream.Optional additives can be added to the molten resin stream in a separatestream injected into extruder 34 and/or added to the extruder on or withthe addition of resin pellets 33 to hopper 30. Extruder 34 forces themolten resin stream through annular die 32 to form tubular filmextrudate 12 which is oriented in the machine and transverse directionswhile the polymer is in the molten state (and while it cools).Orientation is generated by forcing the extrudate to enlarge to passaround a blown bubble of gas (providing orientation in the transversedirection), as well as orientation generated by operating nip rolls 14at a higher speed than the speed of the molten extrudate emerging fromthe annular die (providing orientation in the machine direction). Thetubular extrudate 12 is collapsed into lay-flat tubing 29 after it coolsto a temperature at which it will not self-weld. This process is knownas a “blown” film process.

[0064] Lay-flat tubing 29 can then be converted into the inflatablearticle 20 in the manner illustrated in FIG. 11 and as more particularlyillustrated in FIG. 8. Alternatively, lay-flat tubing 29 could also beconverted into the inflatable article using the arrangement illustratedin FIG. 10, with the lay-flat tubing 29 being the sole film being passedthrough the first and second nips 68 and 72, respectively, instead ofusing two separate films as illustrated in FIG. 10.

[0065]FIGS. 6, 8, illustrate embodiments of a system that furthercomprises a cooling roller 18. FIG. 10 illustrates corresponding coolingroller 74. These cooling rollers are to be maintained at a temperaturebelow the fusing temperatures of films, using conventional coolingtechniques. The cooling roller solidifies the heated portions of thefirst and second films. The present invention is not limited to onecooling roller 18, but rather further encompasses the use of two or morecooling rollers in the process, i.e., downstream of the heated raisedsurface roller. Moreover, any suitable means for cooling could be usedin place of one or more cooling rollers, such as cooled planer surfaces,cooled curved surfaces, cooled clamping surfaces of any shape, coolfluids and gases, etc., as will be understood by persons of skill in theart of film manufacture and processing.

[0066] The cooling roller lowers the temperature of the selected heatedportions of the laminate, in order to cool the heat seals so that theybecome strong enough to undergo further processing without being damagedor weakened. Moreover, the cooling means is preferably immediatelydownstream of the heating means (i.e., the raised surface roll), inorder to reduce heat seepage from the still-hot seals to unheatedportions of film, to prevent unheated portions of laminated article frombecoming hot enough to fuse the films in an area intended to serve as aninflation chamber or inflation passageway.

[0067]FIG. 12 is an exploded diagrammatic view of an exemplary laminatematerial 20. FIG. 13 is a diagrammatic view of a section of a preferredlaminated inflatable article produced in accordance with the presentinvention. Referring to FIG. 12 and FIG. 13, laminate material 20comprises first film 12 heat sealed to second film 13 in a particularheat seal pattern. Laminate 20 has heat sealed portion 40, as well asunsealed portion 41. Heat sealed portion 40 is continuous along themachine direction of inflatable laminate article 20, with sealed portion40 corresponding to a preferred raised surface pattern for raisedsurface roller 16 (FIG. 11) or 70 (FIG. 10). Unsealed portion 41 is alsocontinuous along the machine direction of article 20, with unsealedportion 41 corresponding to a preferred recessed surface pattern (i.e.,background pattern) of raised surface roller 16 and 70. Unsealed portion41 is arranged to form a pattern that includes distinct air chambers,connecting channels, as well as leaving a skirt (i.e., film flaps) foruse in inflating the inflatable article. Optionally, the unsealedportion could further include a passageway in the machine directionwhich serves as a manifold, i.e. connecting each of the passagewaysalong an edge of the article. However, a skirt is preferred.

[0068] The films referred to herein preferably comprise a polyolefin,such as for example a low density polyethylene, a homogeneousethylene/alpha-olefin copolymer (preferably a metallocene-catalyzedethylene/alpha-olefin copolymer), a medium density polyethylene, a highdensity polyethylene, a polyethylene terapthalate, polypropylene, nylon,polyvinylidene chloride (especially methyl acrylate and vinyl chloridecopolymers of vinylidene chloride), polyvinyl alcohol, polyamide, orcombinations thereof.

[0069] Preferably, laminate materials 20 are as thin as possible, inorder to minimize the amount of resin necessary to fabricate laminatematerials 20, but at the same time are thick enough to provide adequatedurability. Preferably, first and second layers film 12 and 13 have agauge thickness of from about 0.1 to about 20 mils. More preferably,each film layer has a total gauge thickness from about 0.5 to about 10mils, more preferably from about 0.8 to about 4 mils, and even morepreferably from about 1.0 to about 3 mils.

[0070] If desired or necessary, various additives are also included withthe films. For example, additives comprise pigments, colorants, fillers,antioxidants, flame retardants, anti-bacterial agents, anti-staticagents, stabilizers, fragrances, odor masking agents, anti-blockingagents, slip agents, and the like. Thus, the present inventionencompasses employing suitable film constituents.

[0071] Preferably first and second films 12 and 13 are hot blown filmshaving an A/B/C/B/A structure which has a total thickness of 1.5 mils.The A layers together make up 86 percent of the total thickness, each ofthe B layers making up 2% of the total thickness, and the C layer makingup 10% of the total thickness. The C layer is an O₂-barrier layer of100% Caplon® B100WP polyamide 6 having a viscosity of Fav=100, obtainedfrom Allied Chemical. Each of the B layers are tie layers made of 100%Plexar® PX165 anhydride modified ethylene copolymer from QunatumChemical. Each of the A layers are a blend of 45% by weight HCX002linear low density polyethylene having a density of 0.941 g/cc and amelt index of 4, obtained from Mobil, 45% by weight LF10218 low densitypolyethylene having a density of 0.918 g/cc and a melt index of 2,obtained from Nova, and 10% by weight SLX9103 metallocene-catalyzedethylene/alpha-olefin copolymer, obtained from Exxon.

[0072] The laminates formed according to the present invention willresist popping when pressure is applied to a localized area becausechannels of air between chambers provide a cushioning effect. Thelaminates also show excellent creep resistance and cushioning propertiesdue to inter-passage of air between bubbles.

[0073] The various terms and phrases utilized throughout this documentare to be given their ordinary meaning as understood by those of skillin the art, except and to the extent that any term or phrase used hereinis referred to and/or elaborated upon in U.S. Pat. No. 5,837,335, toBabrowicz, entitled High Shrink Multilayer Film which Maintains Opticsupon Shrinking, issued Nov. 17, 1998, which is hereby incorporated inits entirety by reference thereto, and which supplements the ordinarymeaning of all terms, phrases, and other descriptions set forth herein.

[0074] In the figures and specification, there have been disclosedpreferred embodiments of the invention. All sub-ranges of all rangesdisclosed are included in the invention and are hereby expresslydisclosed. While specific terms are employed, they are used in a genericand descriptive sense only, and not for the purpose of limiting thescope of the invention being set forth in the following claims.

[0075] Those skilled in the art will appreciate that numerous changesand modifications may be made to the embodiments described herein, andthat such changes and modifications may be made without departing fromthe spirit of the invention.

What is claimed is:
 1. An integrated process for making an inflatablelaminated article, comprising the steps of: (A) extruding a first filmand a second film; (B) cooling the first film and the second film sothat the films will not fuse to one another upon contact with eachother; (C) contacting the first film with the second film; and (D)heating selected portions of at least one of the first and second filmsto a temperature above a fusion temperature, so that the first andsecond films are heat sealed to one another at a selected area, with theselected area providing a heat seal pattern which provides inflatablechambers between the first film and the second film.
 2. The processaccording to claim 1, wherein the selected portions of at least one ofthe first and second films are heated while they are in contact with oneanother, with the heat sealing being carried out using a combination ofheat and pressure.
 3. The process according to claim 1, wherein thecontacting step and the heating step are performed simultaneously. 4.The process according to claim 1, wherein the first and second films areextruded simultaneously.
 5. The process according to claim 1, whereinthe cooling step comprises contacting at least one of the first andsecond films with at least one cooling roll.
 6. The process according toclaim 1, wherein the first and second films are extruded by separateextruders.
 7. The process according to claim 1, wherein the first filmand the second film are each extruded as flat sheets.
 8. The processaccording to claim 1, wherein the heating is performed by passing thefirst and second films together through a nip formed by a pair of rolls,one of the rolls having a patterned raised surface and at least one ofthe pair of rolls being heated.
 9. The process according to claim 8,wherein the patterned roll is heated.
 10. The process according to claim8, wherein the second roll has a raised surface corresponding to theraised surface of the first roll, and the raised surfaces of the firstand second rolls are operatively aligned to heat seal the selectedportions of the first film and the second film.
 11. The processaccording to claim 8, wherein the heated roll has a continuous raisedsurface therearound.
 12. The process according to claim 1, wherein thefirst and second films are heat sealed to one another in a repeatingpattern of sealed and unsealed areas.
 13. The process according to claim1, wherein heating selected portions of at least one film is carried outby wrapping the first film together with the second film in a partialwrap around a heated roller having a raised surface.
 14. The processaccording to claim 13, wherein the heated roller having the raisedsurface has a release coating thereon.
 15. The process according toclaim 13, wherein the raised surface on the heated roller has a surfaceroughness of from 50 to 500 rms.
 16. The process according to claim 13,further comprising cooling the first and second films after heating theselected portions of the films, the cooling being carried out by passingthe first and second films together in a partial wrap around a coolingroller.
 17. The process according to claim 16, wherein the coolingroller has a release coating thereon.
 18. The process according to claim16, wherein the cooling roller has a Shore A hardness of from 40 to 100.19. An integrated process for making an inflatable laminated article,comprising the steps of: (A) extruding a tubular film having an outsidesurface and an inside surface; (B) cooling the tubular film to atemperature low enough that the inside surface of the tubular film iscool enough not to adhere to itself; (C) placing the tubular film intothe lay-flat configuration having a first lay-flat side and a secondlay-flat side, so that a first inside lay-flat surface of the firstlay-flat side of the tubular film is in contact with a second insidelay-flat surface of the second lay-flat side of the tubular film; and(D) heating sealing selected portions of the first lay-flat side of thetubular film to the second lay-flat side of the tubular film, the heatsealing being carried out to provide a pattern of sealed and unsealedareas with the unsealed areas providing inflatable chambers between thefirst lay-flat side of the tubular film and the second lay-flat side ofthe tubular film.
 20. An integrated process for making an inflatablelaminated article, comprising the steps of: (A) extruding a flat filmhaving a first outer surface and a second outer surface; (B) cooling thefilm so that the first outer surface is cool enough not to adhere toitself upon being doubled back against itself; (C) folding the film tomake a crease in a machine direction of the film, with a first leaf ofthe film being on a first side of the crease and a second leaf of thefilm being on a second side of the crease, the first leaf being flatagainst the second leaf so that the first outer surface is doubled backagainst itself, (D) heating sealing selected portions of the first leafto the second leaf, the heat sealing being carried out to provide apattern of sealed and unsealed areas with the unsealed areas providinginflatable chambers between the first leaf and the second leaf.